A New Modification of the Koyanagi Technique for the One-Stage Repair

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provided by Elsevier - Publisher Connector Pediatric Urology A New Modiﬁcation of the Koyanagi Technique for the One-stage Repair of Severe Hypospadias Lei Kang, Guizhen Huang, Li Zeng, Yidong Huang, Xue Ma, Yue Zhang, Miao Yuan, Jie Zhang, and Lugang Huang

OBJECTIVE To describe a new modification of the Koyanagi technique for the one-stage repair of severe hypospadias and its short-term outcomes. PATIENTS AND Our modified Koyanagi technique was performed in 24 patients with severe hypospadias between METHODS February 2012 and January 2015. The age of the patients ranged from 1.9 to 11.9 years (mean = 3.5 years). The flap design was similar to the Koyanagi technique, but our modified technique high- lighted the following points: after the chordee was completely corrected, the urethral plate was recreated using foreskin, and then a U-shaped incision was made on the original and recreated urethral plate (as in the Duplay technique); a pedicled flap of the tunica vaginalis or scrotal dartos was used for additional coverage of the neourethra. RESULTS The operation time lasted from 120 to 150 minutes (mean = 140 minutes). There were 5 patients (20.8%) who developed complications: 4 patients (16.7%) developed a fistula and 1 patient (4.2%) developed dehiscence of the urethra. There were no reported urethral strictures, meatal stenosis, or urethral diverticula. The complications in the 5 patients were successfully addressed with secondary repair, and all patients achieved satisfactory cosmetic and urethral functional results. CONCLUSION The modified Koyanagi technique simplified the operation and better preserved the blood supply to the flap. The additional coverage of the neourethra using a pedicled flap of the tunica vaginalis or scrotal dartos significantly decreased the rate of fistula formation. This technique is highly suitable for the one-stage repair of severe hypospadias with penoscrotal transposition. UROLOGY 93: 175–179, 2016. © 2016 The Authors. Published by Elsevier Inc.

he Koyanagi technique has attracted attention in PATIENTS AND METHODS the last 2 decades for its logical flap design, but it Patient Population was initially not widely used because of its high com- T From February 2012 to January 2015, a total of 24 pa- plication rate. Since then, many modifications of the Koyanagi technique have been introduced, with im- tients with severe hypospadias underwent the modified proved surgical outcomes. Around 2010, the Koyanagi tech- Koyanagi technique at West China Hospital, performed by nique was recommended for patients with severe the same surgical team. Patient age at the time of surgery hypospadias associated with severe chordee in some English ranged from 1.9 to 11.9 years, with a mean age of 3.5 years. monograph of pediatric urology.1 At our institution, we have In all cases, the meatus was at or proximal to the penoscrotal used the Hayashi-modified Koyanagi technique2 for the one- junction, and was classified as penoscrotal (n = 3), peri- stage repair of severe hypospadias since 2001, and we de- neal (n = 9), or scrotal (n = 12). All cases involved severe veloped a new modification in 2012. In this report, we chordee and varying degrees of penoscrotal transposition, present our modified Koyanagi technique along with its and some were accompanied with unilateral inguinal hernia short-term outcomes. (n = 2), unilateral undescended testicle (n = 4), bilateral undescended testicles (n = 3), and chromosomal abnor- malities (n = 3, 46XX in 2 patients and 45XO/46XX in 1 patient). The patients with inguinal hernias and unde- Financial Disclosure: The authors declare that they have no relevant financial scended testicles were surgically cured 3-6 months before interests. From the Department of Pediatric Surgery, West China Hospital, Sichuan Univer- the hypospadias repair, and the 2 patients with 46XX DSD sity, Chengdu, China (disorder of sex development) underwent laparoscopic ex- Address correspondence to: Lugang Huang, M.D., Department of Pediatric Surgery, ploration and excision of the irrelevant gonads 3 months West China Hospital, Sichuan University, Chengdu 610041, China. E-mail: [email protected] in advance of the hypospadias repair. In cases where glans Submitted: October 22, 2015, accepted (with revisions): March 17, 2016 penis diameter was less than 1 cm or penis length was less © 2016 The Authors. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.urology.2016.03.032 175 This is an open access article under the CC BY-NC-ND license 0090-4295 (http://creativecommons.org/licenses/by-nc-nd/4.0/). than 2.5 cm straight, we applied extra hormonotherapy 3-6 carried out if the chordee was still present. A middle in- months before surgery. We used a cream that was made of cision was made at the ventral side of the glans, carefully testosterone propionate (25 mg) and vaseline (10 g), ap- dissecting the glans as a pair of wings. A 1.5-2 cm full- plying locally and externally, 2 times a day, and lasting for thickness incision was made at the midline of the dorsal 1 month. A total of 6 cases were managed with topical prepuce of the penis (Fig. 1B). The prepuce was trans- hormonotherapy in our study. ferred to the ventral side (Fig. 1C), and the distal aspects of the prepuce and the top of the glanular wings were Technique sutured (Fig. 1D). The incisional edges of the foreskin were After general and caudal anesthesia, an 8-10 Fr silicone continuously sutured with 6-0 monocryl to reconstruct the double lumen balloon catheter was placed, the size of which urethral plate, and the foreskin was fixed to the penile al- depended on the development of the penis and the urethra. buginea by 3-5 stitches. A 1.5-1.8 cm width U-shaped in- A circumferential incision was made 5-8 mm proximal to cision was outlined by a marking pen surrounding the the coronary sulcus, and then the foreskin and penile skin original meatus and extending to the distal aspect of the were degloved to the base of the penis between Buck’s fascia penis (Fig. 1E). The skin was then incised along with these and the dartos fascia. The urethral plate and the fibrous markings. The fascia lateral to the U-shaped flap was dis- bands were dissociated to the base of the penile to correct sociated about 1-1.5 cm carefully. The outer edges of the the chordee (Fig. 1A). Usually, we achieved satisfactory flap were sutured together in two layers via a continuous effect beyond the penoscrotal junction. An artificial erec- knock suture with 6-0 monocryl (Fig. 1F). The neourethral tion test was performed after the debonding work was com- meatus was sutured and the penile glans was recon- pleted. Ventral penile lengthening or dorsal plication was structed. A 1.5 cm-width pedicled flap of the tunica vaginalis was dissected carefully, and the lateral edges of it were sewed to the ventral fascia of the penile by interrupted sutures. That way insured an additional coverage for the neourethra, which may reduce the postoperative complication rate (Fig. 1G,H). The scrotal dartos could be another choice for the additional coverage if it was abundant enough. Penoscrotal transposition would be corrected partly after the scrotoplasty. Residual foreskin was used for the phalloplasty (Fig. 1I), and a piece of rubber was placed in the scrotum for drainage, which was removed within 24- 48 hours. After the procedure, a pressure dressing was used to cover the wound for at least a week. The catheter was kept in place for 12-14 days. Figure 2 shows some intraoperative photos.

RESULTS All 24 patients underwent the modified Koyanagi technique for the one-stage repair and the penoscrotal transposition was corrected partly. The operation time ranged from 120 to 150 minutes (mean = 140 minutes). The follow- up period ranged from 6 to 34 months (mean = 11 months). The length of the neourethra ranged from 3 to 7 cm (mean = 4.5 cm). Ultimately, 5 patients developed complications, which consisted of fistula (n = 4) and dehiscence of the urethra (n = 1), but no patient experienced meatal stenosis, urethral stricture, urethral diverticulum, Figure 1. (A) Degloving and chordee correction. (B) A full- bleeding, rotation, or recurrent curvature. As with the prior thickness incision was made at the midline of the dorsal 7 cases, we did not use the tunica vaginalis or scrotal dartos prepuce. (C) The prepuce was transferred to the ventral side. for additional coverage, and there were 3 fistulas belong (D) The distal aspects of the prepuce and the top of the to this group. We started from the 8th case to use the ad- glanular wings were sewed together. (E) The urethral plate ditional coverage (12 with tunica vaginalis and 5 with was reconstructed. The dash line was the marker of the scrotal dartos), and another fistula belong to this group. U-shaped incision. (F) The vascularized pedicle was disso- All 5 patients with complications had their procedures per- ciated, and the outer edges of the flap were sutured to re- formed earlier in the study. These complications were treated construct the neourethra. (G, H) The neourethra was covered with minor secondary operations 1 year after the hypo- with a pedicled flap of the tunica vaginalis. (I) Phalloplasty and scrotoplasty. spadias repair. We evaluated the urethral function by ob- serving micturition and measuring uroflow rate. In our study,

176 UROLOGY 93, 2016 In the early 1980s, Koyanagi et al described the cre- ation of a parameatal foreskin flap for the one-stage repair of proximal hypospadias.8,9 However, the technique was not used widely due to its high complication rate of 47% in the largest series of cases as reported by Koyanagi et al.10 Even so, the advantages of the technique are numerous: there are no anastomoses between the neourethra and the original meatus, effectively reducing the rate of urethral stricture; the procedure always ensures that there is a sufficient flap for the neourethra; the penoscrotal transposition can be corrected simultaneously. Although Nonomura et al argued that the flap had sufficient microcirculation for the urethroplasty11; the high complication rate was mainly attributed to the poor blood supply. Table 1 shows the complications in using the original Koyanagi technique as reported in the literature. Snow and Cartwright16 reported a modification of the Koyanagi technique that significantly improved the blood supply, although there was still a 50% complication rate (2/4 cases). Hayashi et al described a similar modification that preserved the entirety of the vascularized pedicle of the preputial skin, with the flap ventrally advanced through a buttonhole, achieving an acceptable complication rate of 30% (6/20 cases), including a 15% rate (3/20 cases) of Figure 2. Intraoperative photos: (A) Degloving and chordee meatal stenosis.2 Hayashi et al made a further modifica- correction. (B) Incision of the dorsal prepuce. (C) The prepuce tion to the technique to reduce the rate of meatal steno- was transferred ventrally and sewed to the glanular wings. sis, and reported no cases with this complication and with (D) The urethral plate was reconstructed. The U-shaped in- a total complication rate of 8.3% (1/12 cases).17 Emir et al cision was outlined by a marking pen. (E) The pedicle was demonstrated another modification of the Koyanagi tech- dissociated carefully. (F) The neourethra was recon- nique that protected the blood supply, similar to other modi- structed. (G, H) The pedicled flap of the tunica vaginalis was fications, and they emphasized that a circumferential dissected and covered on the neourethra. (I) Phalloplasty anastomosis between the glans and the neourethral meatus and scrotoplasty. A piece of rubber was placed for drainage. should be large enough (20 Fr) to reduce the risk of meatal stenosis, which resulted in an initial success rate of 80% (16/20 cases).18 Sugita et al also published a series of 151 cases of severe hypospadias that underwent urethroplasty we got urinary flow rate data of 18 cases in total, with with their modified Koyanagi technique, resulting in ex- average flow rate of 5.9-11.2 mL/second and maximum flow cellent outcomes with a total complication rate of only rate of 6.7-13.2 mL/second. All patients ultimately achieved 15.9% (24/151 cases).19 Nevertheless, in the modifica- excellent functional and cosmetic results (Supplementary tion described by Sugita et al, penoscrotal transposition was Fig. S1). A total of 3 patients underwent ventral penile not simultaneously corrected during the hypospadias repair. lengthening, which was accomplished by albuginea incis- Table 2 shows the complications in using modified Koyanagi ing and tunica vaginalis patch repairing. There was no com- techniques as reported in the literature. plication that happened in the 3 cases. At our institution, we have employed the Hayashi- modified Koyanagi technique for severe hypospadias since 2001, and have obtained an acceptable complication rate COMMENT of 16.5% (16/97),23 as presented in Table 2. Despite over Severe hypospadias is a challenge for pediatric urologists, and 10 years of experience with this technique, we still felt that there is still great disagreement on the ideal surgical ap- it was difficult to dissect the vascularized pedicle, and the proach, especially with regard to staged or one-stage operations.3 operation always lasted more than 3 hours. Based on these Some reports in the literature have shown that staged repair shortcomings, we made a new modification of the tech- results in better cosmetic outcomes and urethral function,4,5 nique in 2012. but other surgeons have emphasized that the outcomes of one- As described above, our modification emphasized the fol- stage repair have been acceptable and that postoperative com- lowing points: plications could be addressed with minor operations.6 A (1) After the chordee was completely corrected, the ure- systematic 20-year review suggested that staged repair led to thral plate was reconstructed using foreskin, and a U-shaped fewer complications, although 70% of patients who under- incision was subsequently made on the original and went one-stage repair did not require secondary operations.7 recreated urethral plate (as performed in the Duplay

UROLOGY 93, 2016 177 Table 1. Complications using the original Koyanagi technique as reported in the literature No. of Complications (%) Year No. of Meatal Recession or One or More Published Author Patients Fistula Stenosis Stricture Dehiscence Other Complications Overall 1994 Koyanagi et al10 70 15 (21.4) 12 (17.1) 6 (8.6) 0 (0) 0 (0) 0 (0) 33 (47.1) 1996 Hayashi et al12 17 3 (17.7) 3 (17.7) 0 (0) 2 (11.8) 0 (0) 0 (0) 8 (47.1) 1998 Glassberg et al13 14 7 (50) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 7 (50) 2003 DeFoor and 3 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) Wacksman14 2009 Catti et al15 26 5 (19.2) 4 (15.4) 5 (19.2) 11 (38.5) 7 (26.9) – 16 (61.5)

Table 2. Complications using modiﬁed Koyanagi techniques as reported in the literature No. of Complications (%) Year No. of Meatal Recession or One or More Published Author Patients Fistula Stenosis Stricture Dehiscence Other Complications Overall 1994 Snow and 4 2 (50) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 2 (50) Cartwright16 2000 Emir et al18 20 4 (20) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 4 (20) 2001 Hayashi et al2 20 3 (15) 3 (15) 0 (0) 0 (0) 0 (0) 0 (0) 6 (30) 2001 Sugita et al19 151 19 (12.6) 3 (2) 0 (0) 2 (1.3) 0 (0) 0 (0) 24 (15.9) 2003* Jorgensen et al20 9 3 (33.3) 2 (22.2) 0 (0) 0 (0) 0 (0) 0 (0) 5 (55.5) 2007 Hayashi et al17 12 1 (8.3) 0 (0) 0 (0) 0 (0) 0 (0) 0 (0) 1 (8.3) 2009* Catti et al15 31 12 (38.7) 4 (12.9) 1 (3.2) 6 (19.4) 5 (16.1) – 19 (61.3) 2010* Nerli et al21 14 3 (21.4) 1 (7.1) 0 (0) 1 (7.1) 0 (0) 0 (0) 5 (35.7) 2011* Arnaud et al6 21 12 (57.1) 0 (0) 0 (0) 9 (42.9) 0 (0) 5 (23.8) 16 (76.2) 2013* Vepakomma et al22 24 5 (20.8) 2 (8.3) 1 (4.2) 2 (8.3) 1 (4.2) 0 (0) 11 (45.8) 2013* Yuan et al23 97 12 (12.4) 0 (0) 0 (0) 4 (4.1) 0 (0) 0 (0) 16 (16.5) * Performed with the Hayashi-modiﬁed Koyanagi technique.

technique). This shortened the width of the vascularized To reduce the complication rate, a microdissection elec- pedicle and made dissection easier, which can be proven trocautery needle was used for hemostasis, and a piece of by the shortened operation time. The modification also rubber for drainage was necessary. Furthermore, we kept better protected the blood supply to the flap to some extent, the catheter for 12-14 days postoperatively, which was also because the pedicle of the flap was less dissociated. expected to improve outcomes. (2) The additional coverage of the tunica vaginalis or scrotal dartos on the neourethral ventral side significantly decreased the risk of urethrocutaneous fistula, CONCLUSION while also making phalloplasty safer and easier because Our modified Koyanagi technique simplified the opera- of the additional coverage. This technique has previously tion obviously, and effectively preserved the blood supply been applied in hypospadias surgery with excellent to the flap and residual foreskin. Moreover, the use of the results.24,25 tunica vaginalis or scrotal dartos significantly decreased the In our study, the primary outcomes were satisfactory, with rate of fistula. Despite the learning curve, all cases achieved a 20.8% complication rate that was a little higher than the excellent functional and cosmetic results. Our modified rate reported in the case series of the Hayashi-modified Koyanagi technique is highly suitable for the one-stage repair Koyanagi technique. We attribute this slightly higher com- of severe hypospadias, especially in cases with severe chordee plication rate to the learning curve of adopting this modi- and penoscrotal transposition. fied technique, with all complications occurring in the first 15 cases. Of the 4 cases with fistulas, 3 of them belong to the 7 cases without additional coverage of tunica vaginalis or scrotal dartos, and we thought these 3 fistulas were mainly References attributed to the weakness of the local tissue and its poor 1. Hinman F Jr, Baskin LS. Hinman’s Atlas of Pediatric Urologic Surgery. anti-inflammatory ability. Another fistula that happened 2nd ed. Saunders; 2008:726-729. to a case with additional coverage of tunica vaginalis was 2. Hayashi Y, Kojima Y, Mizuno K, et al. The modified Koyanagi repair for severe proximal hypospadias. BJU Int. 2001;87:235-238. due to local infection, which appeared with some puru- 3. Cook A, Khoury AE, Neville C, et al. A multicenter evaluation of lent secretion on the sixth day postoperatively. The only technical preferences for primary hypospadias repair. J Urol. one urethral dehiscence was caused by ischemia of the flap. 2005;174:2354-2357.

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